Method of making same



, Patented June 16, 1953 N TE-o; sTAT BUFFING COMPOSITION FOR METALS'ANDMETHOD F MAKING SAME Hugh A. Stier, Fairfield, Conn., assigno'r to E. E.vSeeley Company, Incorporated, Bridgeport, Conn., incorporation ofConnecticut No Drawing. Application March 19,1951, Serial No. 216,453

' This' inventicn relates to compositions of the so-called lime type foruse in buffingmetals order to polish the same and has for itsparticular-objects the provision of a composition of that character thatis unusuallystable when exposed to atmospheric conditionsand-consequently is capable of retaining its shape and ability to polishmetals for many weeks without disintegration, due to deteriorationthereof, even if unwrapped or if exposed'in opened or leaky containersor otherwise to atmospheric influence.

Thebuffing compositions most commonly in use at the present time arecomposed of an intimate mixture of so-called Vienna lime, hereinafterdefined, and a grease binder, the same being prepared by heating amixture of about equal parts of a fatty acid and a glyceride in asteamjacketed kettle, at about 200 F., and then slowly kneading into theresultant mass several'parts of Vienna lime of about 325 mesh. When thematerials are thoroughly" blended, the mixture is placed in containersand allowed to 0001, Where- -upon the containers are capped or sealedtoexelude moisture and air. However, even with such precautions beingtaken the resultant buffing composition will slake and disintegratewithin but about two or three days, if the humidity i high, say at least50%, and the container is left uncapped during the use thereof.Moreover, if the container is leaky or improperly capped, a slow ordelayed slaking may occur that often results in the bursting of thecontainer in which it is confined. Furthermore, if after the aforesaidcomposition is stripped for use "by removing the wrapper thereon, it isnot promptly used but is allowed to lie around exposed to theatmosphere, then rapid and complete slaking occurs and the materialbecomes useless.

My investigations have led to the discovery of a novel bufiingcomposition which is free from the foregoing defects ordisadv'antageswhen exposed to atmospheric influences, the same being so remarkablystable that even if the container in which it may beconfined springs aleak or is improperly capped-or even if the wrapping ona bufiing blockformed from such a composition is omitted or removed so that such blockis exposed to the atmosphere, such composition will remain in a usablecondition for a month or six weeks in sharp contra-distinction to theaforesaid lime type bufiing composition in common use which willinvariably become slaked within the course of but about two or threedays if so exposed.

In the production of my novel buffing composition, it is preferable toproceed as follows:

Claims. (01. 51-295) nical Bulletins on Abrasives,

28-p'arts of mixed tri-glycerides, desirably comprising a mixturecomposed of about part of steal-in, 2! parts of palmi-tin and 3 parts ofmyristin, are introduced into a jacketed millor mixer wherein it isheated to about 180 F., and until melted. Thereupon, 108 parts ofpowdered calcined Vienna lime, desirably of about 325 mesh, are slowlyadded to the melted glycerides and then the mixture is thoroughlyagitatedffor say 30 minutes, after which it i placed in molds andimmediately chilled. It is essential that an aging period, desirablysome twenty-four hours, he allowed to elapse after the completion of thechilling stage and before the Wrapping and packing of or otherwiseexcluding air from the molded forms, in order to admit of sufficientmoisture attacking the buffing composition obtained from the chilledmold so as to insure the formation of a dense, water-insoluble skin coator protective envelope of an insoluble calcium soap of the, particularfatty acids employed, such envelope being not less than about onesixty-fourth of an inch and desirably at least one thirty-second of aninch in thickness.

in hermetically sealedcontainers though it may be shipped in bulkwithout packaging'the same, if desired. s I

Such skin coat or envelope of insoluble calcium soap serves, it isbelieved, to exclude the further making the buffing composition has thefollowing characteristics, -viz., titre 58-60 0., iodine value max.5,'free fatty acid maxJoleic 5%, acid value -max.1-0, saponificatio'nvalue 1 -195;

The Vienna lime which is referred to herein is described on pages 96-97of part 1 of the Techpublished by the Canadian Dept. of Mines (1927) asfollows:

Vienna lime is a calcined, unhydrated, magnesium limestone or dolomite,and is composed of the oxides of calcium and magnesium. The dolomiteused is a greyish white, fine-grained rock a which occasionally displayscertain characteristic fossils and is composed .of about 55 :per cent Icarbonate of calcium and about 43 per cent car- After the expiration ofthe aging period, the molded block is desirably packed bonate ofmagnesium, with traces of iron, silica, and alumina. For buffingpurposes the lime and magnesia content should, approximately, be in theabove proportions, as otherwise poor results are obtained. There are,however, many dolomites of this composition that would not be suitablesince the fossil content of the rock appears to impart certain necessaryphysical properties. The crux of the invention resides, not in the v useof a mixture of tri-glycerides with Vienna lime for producing a buiilngcomposition but in the employment of a mixture of Vienna lime andtri-glycerides which is potentially capable, after being chilled asaforesaid, of reacting with atmospheric moisture and progressivelyforming in situ on the molded block of bufiing composition awater-insoluble protective skin coat or sealing envelope whicheffectively preserves the enveloped portion of the composition againstdeleterious slaking action by atmospheric moisture for many weeks, allas above explained, thus materially prolonging the polishing capacity ofthe bumng composition.

In lieu of the aforesaid mixture of tri-glycerides,

I may employ a mixture of about equal parts of the tri-glycerides knownas palrnitin, stearin and olein such as exist in tallow, or othermixtures of tri-glycerides, such for example as fish glycerides.However, the amount of free fatty acids present in the glyceridesemployed should range between 3% and 10% of such tri-glycerides anddesirably should be about 5% as, if the amount of free fatty acids isexcessive and substantially exceeds about the aforesaid slaking reactiontends to progressively extend throughout the entire mass of the buffingcomposition within the course of but a few days, as above set forth.

The exact proportions of the Vienna lime and mixed glycerideshereinbefcre specified may be varied but in no event should the Viennalime be less than about 65% nor more than 85% nor should the amount ofmixed glycerides be less than nor more than by weight, of the bufiingcomposition.

Various modifications of the method and ingredients as well as theproportions thereof which are employed may be made without departingfrom the spirit of the invention as embraced within the scope of theappended claims.

Having thus described the invention, what I claim is:

'1. The method of making a metalpolishing composition, which consistsessentially of heating from about 15 to 35 parts, by weight, of amixture of tri-glycerides belonging to the group consisting of palmitin,stearin, olein and myristin containing from about 3% to 10%, by Weightof such mixture, of free fatty acids, with about 65 to 85 parts, byweight, of finely powdered Vienna lime to a temperature above themelting point of the tri-glycerides while thoroughly agitating the mass,then delivering the mixture into molds and immediately chilling the sametherein suflicient- 1y to solidify the tri-glyceride content thereof,

4 removing the resultant cast product from the molds and exposing thesame to a moist atmosphere until a moisture-impervious skin-coat of aninsoluble soap of a thickness of but a small fraction of an inch but-notless than about A of an inch has formed in situ on such cast product.

2. The method of making a metal-polishing composition, which consistsessentially of heating from about 15 to 35 parts, by weight, of amixture of tallow glycerides, containing from about 3% to 10%, by weightof the mixture, of free fatty acids, with about to parts, by weight, ofVienna lime, in the form of a fine powder, to a temperature above themelting point of glycerides while thoroughly agitating the mass, thendelivering the mixture into molds and therein immediately chilling thesame sufficiently to solidify the tallow content thereof, removing theresultant cast product from the molds and exposing the same to a moistatmosphere until a moisture-impervious skin-coat of an insoluble calciumsoap of a thickness of but a small fraction of an inch but not less thanabout one thirty-second of an inch has formed in situ on the resultantproduct and then hermetically sealing the product so obtained in acontainer.

3. A buffing composition for polishing metals, consisting essentially ofa cast solid composed of an intimate mixture of about 15 to 35 parts, byweight, of tallow tri-glyoerides, containing about 3% to 10% of freefatty acids, and about 65 to 85 parts, by weight of the cast solid, offinely divided Vienna lime, the cast solid being encased in amoisture-impervious protective skin-coat consisting of a calcium soapintegrally formed in situ thereon and of a thickness of but a smallfraction of an inch but not less than about fl th of an inch.

4. A buffing composition for polishing metals, consisting essentially ofa cast solid composed principally of about 65 to 85 parts, by weight ofVienna lime and about 15 to 35 parts, by weight of a plurality oftri-glycerides belonging to the group consisting of palmitin, stearin,olein and myristin, about 3% to 10% of which triglycerides consist offree fatty acids, said solid being encased in a moisture-imperviousskincoat of a thickness of but a small fraction of an inch, but not lessthan about A, of an inch, which is composed of a calcium soap that isintegrally formed thereon.

5. A bufiing composition, as claimed in claim 4, wherein the skin-coatis at least about one thirty-second of an inch thick.

HUGH A. STIER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 609,326 Bogani Aug. 16, 1898 1,743,865 Pilgrim Jan. 14, 19302,119,159 Glenning May 31, 1938

1. THE METHOD OF MAKING A METAL-POLISHING COMPOSITION, WHICH CONSISTSESSENTIALLY OF HEATING FROM ABOUT 15 TO 35 PARTS, BY WEIGHT, OF AMIXTURE OF TRI-GLYCERIDES BELONGING TO THE GROUP CONSISTING OF PALMITIN,STEARIN, OLEIN AND MYRISTIN CONTAINING FROM ABOUT 3% TO 10%, BY WEIGHTOF SUCH MIXTURE, OF FREE FATTY ACIDS, WITH ABOUT 65 TO 85 PARTS, BYWEIGHT, OF FINELY POWDERED VIENNA LIME TO A TEMPERATURE ABOVE THEMELTING POINT OF THE TRI-GLYCERIDES WHILE THOROUGHLY AGITATING THE MAS,THEN DELIVERING THE MIXTURE INTO MOLDS AND IMMEDIATELY CHILLING THE SAMETHEREIN SUFFICIENTLY TO SOLIDIFY THE TRI-GLYCERIDE CONTENT THEREOF,REMOVING THE RESULTANT CAST PRODUCT FROM THE MOLDS AND EXPOSING THE SAMETO A MOIST ATMOSPHERE UNTIL A MOISTURE-IMPERVIOUS SKIN-COAT OF ANINSOLUBLE SOAP OF A THICKNESS OF BUT A SMALL FRACTION OF AN INCH BUT NOTLESS THAN ABOUT 1/64 OF AN INCH HAS FORMED IN SITU ON SUCH CAST PRODUCT.